肖特基式石墨烯氢敏器件的构筑及其性能研究

Hydrogen as a kind of ideal clean energy is widely applied. But it easily cause explosion. For a long time, people are looking for one kind of hydrogen sensor with good selectivity, high sensitivity, low energy consumption, good stability, simple manufacturing process and easy integration. In this study, we put forward to fabricate a schottky-type field-effect hydrogen device based on a micrometre graphene in which a nonsymmetrical Schottky contact at one end of device is deliberately introduced. Ultrasound-solvent lift-off method is used for stripping micrometre graphene. The palladium and platinum nanoparticles is modified on the graphene by solution chemical reduction method, which serve as sensitive sites for hydrogen molecule. The graphene modified with noble metal nanoparticles is transferred onto the micro-gap electrodes using plolymethyl methacrylate (PMMA) film transferring technology. The schottky-type field-effect device based on micrometre graphene is built after one contact of graphene and the gold electrode is welded using silver plaster. The electrical property of the schottky-type field-effect device based on graphene will be studied. The sensor response to hydrogen under different gate voltage will be investigated. The changes of carrier concentration on the graphene and Schottky barrier will be studied when graphene modified with platinum or palladium nanoparticles adsorbs hydrogen molecule. The sensing mechanism of the schottky-type field-effect device based on micrometre graphene will be clarified. The test method of schottky-type hydrogen device will be established. It will provide technical foundation for rapid and high sensitive detection of hydrogen in room temperature.

氢气是一种理想的清洁能源，应用广泛，但易引起爆炸。长期以来，人们一直在寻找选择性好、灵敏度高、能耗低、稳定性好、制作工艺简单且易集成的氢气传感器。本研究在器件中引入不对称肖特基势垒，提出研制一种基于微米尺度石墨烯的肖特基式场效应管氢敏器件。项目利用超声-溶剂剥离法制备微米尺度石墨烯，用化学还原法将钯和铂纳米粒子分别修饰到石墨烯表面 ，充当感知氢气分子的敏感位点，采用聚甲基丙烯酸甲酯膜转移技术将贵金属修饰的石墨烯转移至微米间隙电极上，用银浆焊接石墨烯与金电极接触的一端，构筑出肖特基式石墨烯场效应管器件；研究肖特基式石墨烯场效应管器件的电学特性，考察不同栅压下传感器对氢气的敏感响应；研究修饰钯或铂纳米粒子的石墨烯与氢气分子作用后载流子浓度和肖特基势垒的变化规律，阐明钯和铂修饰石墨烯传感器对氢气的敏感机理，建立肖特基式石墨烯氢敏器件的测试方法，为室温下氢气的灵敏、快速检测提供技术基础。

氢气是一种理想的清洁能源，但易引起爆炸。人们一直在寻找选择性好、灵敏度高、能耗低和稳定性好的氢气传感器。项目用化学还原等方法将钯，铂，NiO和SnO2纳米颗粒分别修饰到石墨烯表面，充当感知氢气分子的敏感位点，构筑出石墨烯基传感器件，为室温下氢气的灵敏、快速检测提供技术基础。此外，针对特定的苦味酸分子，设计合成出1–芘丁酸–氨基–β–环糊精，发展出苦味酸传感器件。具体研究成果概括如下：.1、rGO传感器对重金属离子Hg2+的选择性检测。采用氧化超声分散法制备出氧化石墨烯，再将GO自组装在微米间隙电极上，用电化学还原得到rGO，研制出rGO传感器件。该传感器对水溶液中Hg2+的响应灵敏性高，检测线性范围为40 nM-3240 nM，检测灵敏度和检出限分别为0.08833 nA nM-1和7.8 nM。.2、Pd/rGO传感器对H2的敏感响应。用化学还原法制备出Pd纳米粒子，通过电化学方法，将Pd纳米粒子沉积到还原氧化石墨烯传感器件表面，充当感知氢气分子的敏感位点，研制出一种室温氢气传感器件，并探讨了敏感响应机制。.3、SnO2/rGO传感器对H2的敏感响应。用水热法制备出SnO2纳米粒子，通过电化学方法，将SnO2纳米粒子沉积到还原氧化石墨烯传感器件表面，充当感知氢气分子的敏感位点，研制出一种室温氢气传感器件，并阐明了敏感响应机理。.4、Pt/rGO传感器对H2的敏感响应。用化学还原法制备出Pt纳米粒子，再通过冷冻干燥法，将Pt纳米粒子修饰到氧化石墨烯表面，充当感知氢气分子的敏感位点。将Pt/rGO做为敏感材料涂覆在陶瓷管上，研制出一种氢气传感器件。.5、NiO/rGO传感器对H2的敏感响应。将NiO纳米粒子与氧化石墨烯溶液混合，用冷冻干燥法制备出NiO/rGO复合材料。将NiO/rGO复合材料做为敏感材料涂覆在陶瓷管上，研制出一种氢气传感器件。.6、设计研制出一种苦味酸传感器件。设计合成出含芘结构的环糊精，用来修饰还原氧化石墨烯器件。该传感器对苦味酸的线性响应范围为5 μM-215 μM，检测灵敏度和检出限分别为0.00613 μA μM-1和0.54 μM。该传感器对苦味酸具有较高的灵敏度和选择性，这主要由于β–环糊精的独特结构与苦味酸的疏水基团–NO2相结合。